Question

Given f(x) = sinx - cosx on [0, pi], on what interval(s) is f'(x) > 0?

Answer 1

\[f'(x)>0
\]Means that \(f(x)\) is increasing.

Answer 2

You could just take the derivative: \[
f'(x)=\cos(x)+\sin(x)>0
\]

Answer 3

So it looks like the interval is \([0,3\pi/4)\).

Answer 4

so you just have to plug and chug in numbers? How do you do the problem with the math behind it?